No AES-NI Support in OS X?

One of the features of Arrandale (and all other Westmere derived architectures) is support for AES-NI. The six instructions that fall under the AES-NI umbrella can accelerate encryption and decryption operations.

Microsoft's full disk encryption feature in Windows 7, BitLocker, is AES-NI accelerated. Simply upgrading to a supported Core i5 or i7 processor gives you better disk performance with BitLocker turned on.

While I'm still waiting for Apple to get back to me on a number of questions, I decided to see if FileVault, OS X's encryption system was AES-NI accelerated as well.

I ran XBench's disk tests on an encrypted home directory and then again on a completely unencrypted portion of the drive. If Apple takes advantage of the Core i5's AES-NI I should see a smaller drop in performance on the new MacBook Pro compared to the old one:

FileVault Disk Performance Comparison
  Sequential Read (256KB) Sequential Write (256KB) Random Read (4KB) Random Write (4KB)
Core 2 Duo MacBook Pro - FV Off 172.5 MB/s 127.1 MB/s 10.9 MB/s 134.1 MB/s
Core 2 Duo MacBook Pro - FV On 79.5 MB/s 61.9 MB/s 6.8 MB/s 67.8 MB/s
Core i5 MacBook Pro - FV Off 175.1 MB/s 160.0 MB/s 21.5 MB/s 112.7 MB/s
Core i5 MacBook Pro - FV On 80.5 MB/s 66.6 MB/s 13.2 MB/s 61.0 MB/s

And it looks like we have no AES-NI support in FileVault at least. It's not terribly surprising. Apple usually takes a while to implement new features enabled by hardware changes. Remember how long it took Apple to get GPU accelerated video decoding?

These numbers do tell us something else entirely though: the new MacBook Pro appears to offer better SATA performance.

Not too long ago I published a quick look at 6Gbps SATA controller performance and concluded, among other things, that Intel's SATA controllers are quite good. The numbers above support that theory as disk performance has gone up considerably compared to last year's NVIDIA based MacBook Pro. While random write speed dropped a bit, random read and sequential write performance jumped up significantly.

This is quite noticeable with a SSD but less of a problem with a hard drive. Needless to say Apple's return to Intel is a good thing, especially because we didn't have to give up NVIDIA's graphics.

They’re Actually Faster Apple's GPU Switching Technology
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  • MySchizoBuddy - Wednesday, April 14, 2010 - link

    sorry i was looking at the 620UM. someone needs more clearer names Reply
  • DLeRium - Wednesday, April 14, 2010 - link

    seriously? Didn't the 15" get the 9600GT in the two higher level ones?

    The 9400M was a 13" MBP model and also for the base 15". But clearly the 330M GT is designed to replace the 9600M GT not the 9400M. The 320M GT now in the 13" MBPs is designed to replace the 9400M. The base 15" MBP got an upgrade this year from 9400M to 330M GT, but it's clearly two different classes.

    I would've preferred if you benched the 330M GT against the 9600M GT which was an upgrade to the old 8600M GT that I have from an early 2008 MBP. The 9400M is just the wrong card to bench against.
    Reply
  • DLeRium - Wednesday, April 14, 2010 - link

    so yes, it's obvious the 330 will be faster than the 9400, but how much faster than the 9600? I think that's the most crucial question.

    The 320 should've been pitted against the 9400 and 330 against 9600.
    Reply
  • Anand Lal Shimpi - Wednesday, April 14, 2010 - link

    I agree, I just don't have any of the MBPs with the 9600M around the lab anymore :)

    Take care,
    Anand
    Reply
  • DLeRium - Thursday, April 15, 2010 - link

    aww how unfortunate. I just figured that since you put the 2.53 ghz MBP in comparison that it would be the 9600M one. Oh well. I'm glad you at least included my 2008 MBP in the benches (way to make me feel like I need to upgrade :D )

    Great review
    Reply
  • Anand Lal Shimpi - Thursday, April 15, 2010 - link

    I always try to have at least n-2 generations of MacBook Pro hardware laying around for comparisons like this :)

    Take care,
    Anand
    Reply
  • youguy - Wednesday, April 14, 2010 - link

    With SSDs offered as an option, why aren't we seeing TRIM support in Snow Leopard? Reply
  • Griswold - Thursday, April 15, 2010 - link

    Ask steve@apple.com

    Should he respond, it might be something along the line of "We dont believe people want to trim anything". Or that SSDs "are a mess".

    Good luck.
    Reply
  • ggathagan - Thursday, April 15, 2010 - link

    Battery life would be my guess.
    To a lesser extent, I suppose a 5400rpm drive also generates less heat than a 7200, but I don't know if the difference would be significant.
    Reply
  • Brian Klug - Thursday, April 15, 2010 - link

    You know, that used to be my thought as well, and I was totally concerned back when the first notebook form factor 7200 RPM drives swung around, but there's no truth to those assumptions anymore. In fact, back then I found that the newer 7kRPM drive actually gave me *better* battery life and reported cooler temps through SMART. Not sure how, but that's just how it worked out. Obviously there are going to be small differences, but there's also that HUGI (hurry up and get idle) consideration to be made here the same way intel rationalizes turbo mode on a notebook; get the task done fast, then go into a low power state. It ends up being a net energy savings.

    But it's obvious that heat/battery aren't the real reasons; the 7K RPM drives are still options, just not default. $50 isn't that much for a "pro" notebook is my point.

    At the same point, a platter drive is a platter drive; the performance gains aren't going to be anywhere near what you'll see with an SSD, so perhaps it makes more sense to just forget about upgrading the HDD and save the $50 for your SSD. There are arguments for both I suppose.

    -Brian
    Reply

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